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Microsoft Security Response CenterCVE-2026-83881

Windows exFAT File System Elevation of Privilege Vulnerability

HighVendor CVSS 7.8 / 10 1 CVE Published Oct 13, 2026 at 7:00 AM UTC

Summary

Heap-based buffer overflow in Windows exFAT File System allows an authorized attacker to elevate privileges locally.

Products covered

  • Windows 10 Version 1809 for 32-bit Systems

  • Windows 10 Version 1809 for x64-based Systems

  • Windows Server 2019

  • Windows Server 2019 (Server Core installation)

  • Windows Server 2022

  • Windows Server 2022 (Server Core installation)

  • Windows 10 Version 21H2 for 32-bit Systems

  • Windows 10 Version 21H2 for ARM64-based Systems

Show 24 more products
  • Windows 10 Version 21H2 for x64-based Systems

  • Windows 10 Version 22H2 for x64-based Systems

  • Windows 10 Version 22H2 for ARM64-based Systems

  • Windows 10 Version 22H2 for 32-bit Systems

  • Windows Server 2025 (Server Core installation)

  • Windows 11 Version 25H2 for ARM64-based Systems

  • Windows 11 Version 25H2 for x64-based Systems

  • Windows 11 Version 23H2 for ARM64-based Systems

  • Windows 11 Version 23H2 for x64-based Systems

  • Windows 11 Version 24H2 for ARM64-based Systems

  • Windows 11 Version 24H2 for x64-based Systems

  • Windows Server 2025

  • Windows 11 version 26H1 for x64-based Systems

  • Windows 11 Version 26H1 for ARM64-based Systems

  • Windows 10 Version 1607 for 32-bit Systems

  • Windows 10 Version 1607 for x64-based Systems

  • Windows Server 2016

  • Windows Server 2016 (Server Core installation)

  • Windows Server 2012

  • Windows Server 2012 (Server Core installation)

  • Windows Server 2012 R2

  • Windows Server 2012 R2 (Server Core installation)

  • Windows 11 Version 26H2 for ARM64-based Systems

  • Windows 11 Version 26H2 for x64-based Systems

Remediation

Install KB5126651. Install KB5126655. Install KB5126657. Install KB5126646. Install KB5127648. Install KB5126653. Install KB5127646. Install KB5126868. Install KB5126835. Install KB5126836.

Vendor-listed fixes

  • 10.0.17763.9376

  • 10.0.20348.5761

  • 10.0.19044.7807

  • 10.0.19045.7807

  • 10.0.26100.33650

  • 10.0.26200.9711

  • 10.0.22631.7652

  • 10.0.26100.9711

Show 5 more fixes
  • 10.0.28000.3231

  • 10.0.14393.9612

  • 6.2.9200.26434

  • 6.3.9600.23470

  • 10.0.26300.9711

CVEs in this advisory 1

Update history

What changed in later vendor updates

SecurityAlert records field-level changes from the point we begin following a bulletin. Earlier vendor changes may not have a field-by-field record.

    • Added fixed versions: 10.0.19045.7807.

Updates

  1. Published by Microsoft Security Response Center

    The publication date reported by the vendor.

  2. Added to SecurityAlert

    We collected the advisory from the official source.

  3. Confirmed at the source

    Our collector saw this advisory during a later source check.